U.S. Pat. No. 3,997,239 describes a microscope composed of shell-like parts. The microscope stage is mounted to an arm and can be moved by an eccentric cam in the direction of the optical axis of the microscope. No artificial illumination is provided for the samples located on the microscope stage. Neither is there any provision for a fine adjustment of the microscope stage.
Similarly, U.S. Pat. No. 4,361,377 describes a portable compact microscope which has a plurality of adjusting elements provided on the housing. The sample to be examined is introduced through a slot in the housing. Illumination is provided by at least one conventional incandescent lamp which is connectable to a battery for power supply. No provision is made for an adjustable microscope stage.
German Patent Applications DE 102 46 277 A1 and DE 102 46 275 A1 describe a microscope whose stand consists of a minimum number of shell parts. In addition, the stand of the microscope is provided with an adjusting knob for focusing. Moreover, the microscope is narrow relative to the height of the stand, and the number of control elements is reduced to a minimum. The microscope has only a few corners and edges, which considerably reduces the risk of damage. However, the microscope is not equipped with any stage adjustment mechanism which would allow fine or coarse adjustment of the microscope stage.
The Leitz HM microscope already describes a coarse and fine focus adjustment including a one-piece control knob. Coarse and fine focus adjustment is accomplished by a plurality of mechanical transmission elements. This design does not provide a cost-effective solution.